Recently, wireless devices for mobile communications including a handy telephone have been getting smaller and more multi-functional. Accordingly, as an antenna to be mounted on such a compact device, a built-in type has become popular.
Here will be described a conventional built-in type antenna with reference to FIG. 10 and FIG. 11. FIG. 10 is a perspective view showing the appearance of a conventional antenna. Insulating resin-made core 1 has body 1A generally shaped into a rectangular parallelepiped. Three projections 1C, which project from each periphery of three corners of body 1A, are disposed in parallel with each other. Each of projections 1C has hole 1B therein.
Antenna element 2, which is made of a metallic thin plate, is calked on the upper side of core 1 with projections 1D disposed on the upper surface of body 1A of core 1.
Antenna element 2 contains feeding terminal 2A. Feeding terminal 2A projects in a slanting-down direction from a periphery of the corner having no projection 1C of core 1. Conventional antenna 3 is structured above.
FIG. 11 shows how antenna 3 is mounted on a wireless device—specifically, shows the state previous to be accommodated in case 4 of a wireless device for mobile communications.
Antenna 3 is placed in a space adjacent to wiring board 5 in case 4, using three wood screws 6 each of which is through hole 1B of projection 1C and boss 4A of case 4 corresponding to each projection 1C.
Wiring board 5 includes communications circuit 5B located in area 5C shown by the dash lines in FIG. 11. The explanation of the components (not shown) of circuit 5B is omitted. When antenna 3 is fixed in case 4, the tip of feeding terminal 2A integrally formed with antenna element 2 has a tight contact with feeding section 5A (which is further connected with communications circuit 5B) of wiring board 5. With the structure, an operation performed by circuit 5B establishes wireless communications via antenna 3.
References relating to the prior-art technology described above are introduced in, for example, Japanese Patent Non-examined Publications No. H11-163613 and H10-13287.
A prior art antenna, as described above, is mounted on a wireless device by wood screws 6, which inconveniently decreases mounting efficiencies and increases production costs. Furthermore, due to the structure in which feeding terminal 2A makes a tight contact with feeding section 5A of wiring board 5, the prior-art antenna cannot ensure stability in electrical connections when an impact load is applied thereto. It has been a pending problem to be improved.